1. Field of the Invention
This invention relates to an apparatus for manufacturing objects and conveying the same objects through a series of secondary operations and, more specifically, to such a process utilizing an offset bandolier.
2. Background Information
Many mass produced metal articles are created using a cold forming process. This process uses force, rather than heat, to form and/or shape parts into the desired configuration. Examples of cold forming processes include, but are not limited to, cold heading, cold roll forming, and other methods. Each of these methods is well known within the industry. Other methods of mass producing metal articles include various forms of machining.
Such production methods described above do not allow for the production rates that can be realized by producing products in a progressive die. A progressive die can allow the use of a bandolier, which is, generally, an elongated conveyor belt to which the raw material, or a partially completed work piece, may be removably coupled. Typically, the work piece is coupled to a retention member on the bandolier. The retention member positions the work piece above, and possibly laterally offset to, the centerline of the bandolier. Such dies may require a corrective device structured to laterally reposition the work piece. Work stations are disposed adjacent to, or above, the bandolier. As the bandolier advances, the various work stations each act upon one or more of the work pieces.
The positioning of the work stations depends upon the operation being performed on the work piece and/or the shape of the work piece. For example, in U.S. Pat. No. 7,383,760, noted above, a generally cylindrical segment of wire (the work piece) is formed into a flechette, or dart. Thus, one work station acts upon one end of the wire segment to form fins. A later work station acts upon the opposite end to form a point. Thus, these two work stations are disposed upon opposite sides of the bandolier. Other work stations may be bifurcated, that is, the work station may have components located on both sides of the bandolier. These components are structured to move over top of the bandolier to act upon the work piece.
As the bandolier progresses, typically in discrete “steps,” the work piece progresses through the various work stations. It is noted that the work piece is not acted upon at each step. That is, a work piece may enter the first work station at the first progression. The bandolier may then advance several progressions before the work piece reaches the second work station. Such non-active steps, or “feed progressions,” may be due to the fact that allowance is being made for future changes in the number, type, and/or location of the work stations, or, due to the fact that forming tools and equipment require a certain amount of space. It is further noted that a typical cold forming and machining process described above produces one part after another, but does not allow for subsequent secondary operations, such as heat treating, coating, assembly operations, etc.
The cold forming process described above may have inherent disadvantages. For example, in order for the various work stations to align properly with the work piece, the work piece must be in a known orientation relative to the bandolier. Typically, the work piece is oriented either laterally relative to the longitudinal axis of the bandolier, or the axis of the work piece extends normal, i.e. straight up, relative to the surface of the bandolier. However, when only one side of the work piece is acted upon, e.g. forming the fins on one end of a flechette, the work piece may become laterally offset relative the bandolier. Thus, the work piece must either be held in position at each work station, or, the work piece must be reoriented in between work stations.
As noted above, the work piece may be offset relative to the centerline of the bandolier. Such an offset has been, typically, fairly minor. For example, with the flechette described above, the “fin” side of the work piece typically extended further over the lateral edge of the bandolier than the “nose” side of the work piece. However, while the work piece could be offset, or shifted, to one side of the bandolier, at least a portion of the work piece was located over the bandolier.